VDB Reuse - View model says it is read only

I am working on a test script for Data roles and I am also testing Data roles with VDB Reuse.

I connected to VDB using the process described in section 10.6 in [1]
This process creates a source model.

Then I created view model using transformation from this source model.
Now, when I try to copy some procedure to this view model everthing works, but when I try to delete this coppied procedure JBDS gives me an error warning that this model is READ ONLY. I shouldn't be read only, should it?

BUT, when I try to cut this procedure from the model (Ctrl + X) everything works, without error warnings. Also in the properties of this model isn't the checkbox for "read only" checked.

[1] http://docs.jboss.org/teiid/designer/8.3/user-guide/en-US/html_single/